On Tue, Aug 26, 2008 at 12:53 AM, Ingo Molnar <mingo@xxxxxxx> wrote: > > * David Miller <davem@xxxxxxxxxxxxx> wrote: > >> From: Ingo Molnar <mingo@xxxxxxx> >> Date: Tue, 26 Aug 2008 09:22:20 +0200 >> >> > And i guess the next generation of 4K CPUs support should just get away >> > from cpumask_t-on-kernel-stack model altogether, as the current model is >> > not maintainable. We tried the on-kernel-stack variant, and it really >> > does not work reliably. We can fix this in v2.6.28. >> >> I recenetly did some work on sparc64 to use cpumask pointers as much >> as possible. >> >> The only case that didn't work was due to a limitation in arch >> interfaces for the new generic smp_call_function() code. It passes a >> cpumask_t instead of a pointer to one via >> arch_send_call_function_ipi(). >> >> But other than that, the whole sparc64 SMP stuff uses cpumask_t >> pointers only. wonder if could use "unsigned long *" directly. so could dyn_array directly like int cpumask_size; unsigned long *online_cpu_map; DEFINE_DYN_ARRAY(online_cpu_map, sizeof(unsigned long), cpumask_size, PAGE_SIZE, NULL); and after nr_cpu_ids is assigned, have cpumask_size = (nr_cpu_ids + sizeof(unsigned long) - 1)/sizeof(unsigned long); then we could NR_CPUS=4096 kernel to small system. ... YH -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
